f\  1 1 1  r  '   if 


G    L910. 


(  .  S.  DEPAR  rMENT   OF  AGRICULTURE, 

Bl  i;  I  A  l     OF   PLANT   INDUSTRY— Circular  No.  47. 
(JALLOWAY,  Chiel  of  Bureau. 


PRICKLY  COMFREY  AS  A  FORAGE 

CROP. 


II.  \.  VINALL, 
Scientific     Assistant,  Office  of  Forage-Crop 

i  \\  ESTIG  ITIONS. 


WASHINGTON    !  GOVERNMENT  PRINT!' 


UNIV  OF  FL  LIP 
DOCUMENT^  Dp 


OEPOSITORY 


BUREAU    OF    PLANT   INDUSTRY 


Chief  of  Bureau,  Beverly  T.  Galloway. 
As$ista7it  Chief  of  Bureau,  Albert  F.  Wi 
Editor,  J.  E.  Rockwell. 
Chief  Chrk,  James  E.  Joni  s. 
[Cir.  47] 


PRICKLY  COMFREY   \S  A  FORAGE  CROP." 


INTRODUCTION 

Prickly  comfrey  {Symphytum  asperrimum  Donn)  is  a  perennial 
herbaceous  plant,  a  native  of  the  Caucasus  region  of  Europe,  which 
was  introduced  into  England  as  early  as  1801.  Apparently  it  was 
first  grow  n  in  the  United  States  near  Richmond,  Va.,  in  I  s  7  ( ; .  The 
only  recorded  importation  of  this  plant  by  the  Department  of  Agri- 
culture was  made  in  February,  1899,  from  France,  in  L830  it 
attracted  attention  in  England  as  a  forage  plant,  and  from  thai  date 
until  1876  or  later  some  little  interesi  was  exhibited  in  its  dissemina- 
tion by  agriculturists.  Thomas  Christy,  jr.,  of  London,  was  especially 
prominent  in  it's  advertisement  and  published  a  lengthy  article6 
descriptive  of  its  value  as  a  food  for  hogs,  sheep,  and  dairy  cows, 
especially    as  a  soiling  crop  and  in  the  form  of  ensilage. 

Although  prickh  comfrej  was  grown  rather  extensively  years  ago 
in  Europe  and  to  some  extent  in  the  United  States,  it  has  never 
attained  any  considerable  importance  in  either  country  as  a  forage 
crop.  At  the  present  time  it  is  probably  grown  more  generally  in 
Germany  than  in  an\  other  country,  and  its  success  there  may  be 
ascribed  to  the  intensive  methods  of  cultivation  employed  on  small 
farms,  a  practice  which  calls  for  some  crop  that  will  re-pond  with 
\  ields  to  heavy  applical  ions  of  fertilizer.  Only  under  such  meth- 
ods can  the  yields  of  forage  mentioned  in  reports  from  Germany  be 
expected.  None  of  the  government  experiment  stations  in  European 
countries  have  seen  lit  to  commend  prickly  comfrey  in  their  reports 
-"  far  as  noted. 

f  Prickly  comfrey  has  been  grown  a-  a  forage  crop  to  .-nine  extent  in  Europe,  and  in 
scattered  instances  with  success  in  this  country,  Its  general  standing,  however,  lias 
not  seemed  to  warrant  an  extended  trial  by  the  Department  of  Agriculture.  Recently 
advertisements  making  exaggerated  claims  regarding  its  value  as  a  forage  crop 
have  appeared  in  newspapers  ami  circulars,  it  is  therefore  deemed  advisable  to  pub- 
lish in  a  concise  form  the  results  of  tesis  of  this  crop  at  several  state  experiment  sta 
1  ions,  together  with  a  brief  description  of  tin-  plant  ami  directions  for  its  culture.  This 
will  enable  intending  growers  to  draw  their  own  conclusions  as  to  its  probable  value 
for  their  purposes.     I'.   T   Galloway,  Chiefo/Bu 

^Christy,  Thomas,  jr.     Forage  Plants  and  Their  Economic  Conservation  li 
New  System  of  "Ensilage,"  Part  1.     London,  is;;. 
[Cli 


4  PRICKL5    COMFREY    AS    A    FORAGE    CROP. 

DESCRIPTION  OF  PRICKLY  COMFREY. 

The  seed  stalks  of  prickly  comfrey  reach  a  height  of  2  to  4  feet  and 
are  surrounded  by  numerous  long,  heavy,  rough  leave-  of  a  dark- 
green  color  somewhat  mucilaginous  in  texture.  (See  fig.  1.)  The 
bright-blue  flowers  are  borne  in  nodding,  one-sided  cluster-  (fig.  2,  .1  . 
The  roots  are  large  and  fleshy  and  in  loose  soil  will  reach  a  depth  of 


Sot* 
WmMmmm 


j^K-SBsppip 


Fig.  I      a  planl  »f  prickly  cotufrey  in  bloom. 

8  or  9  l'eet.      The  plant  is  hardy  and  will  endure  considerable  cold  or 
drought,  making  a  very  rapid  growth  when  conditions  are  favorable. 

PROPAGATION  OF  THE  PLANTS. 

A.lthough  the  prickly  comfre}  produces  targe  crops  of  seed,  only  a 
small  percentage  of  this  seed  will  germinate,  so  it  is  generally  found 
more  practicable  to  plant  new  held-  by  division  of  the  roots  than  by 

l<   if.   171 


PBK   KL^     I  i'\|  !  HE\     A.S     \     l  ,  h;  \i,|.    ri;,.|' 


6  PRICKLJ    COMFREY     \s    A    FORAGE    CROP. 

seed.  These  root  cuttings  may  be  cither  crown  cuttings  (fig.  2,  J!  I  or 
transverse  sections  of  the  lower  taproots  (fig.  2,  C),  and  they  may  be 
quite  small,  so  that  the  number  secured  from  a  single  plant  will  be 
considerable  even  in  one  year.  They  are  planted  in  rows,  usually 
about  3  feet  apart  each  way,  or  3  feet  between  the  rows  and  l\  to  2 
feet  apart  in  the  row,  the  distance  depending  on  the  fertility  of  the 
soil.  When  first  planted,  the  young  sets  must  he  given  frequent  and 
thorough  cultivation.  The  sets  made  from  crown  cuttings  usually 
bloom  the  first  year,  while  those  made  from  pieces  of  the  taproots  will 
not  bloom  as  a  rule  until  the  second  reason. 

CULTURE  OF  THE  CROP. 

Cultivation  should  be  continued  after  each  cutting  until  the  plants 
are  large  enough  to  shade  the  ground,  and  a  light  top-dressing  of 
manure  should  be  given  the  field  after  each  cutting  if  large  and  fre- 
quent crops  are  to  be  expected.  The  cuttings  should  always  be  made 
before  seed  has  formed.  From  three  to  six  crops  a  year  may  be  ob- 
tained, and  in  good  soil  a  field  is  supposed  to  last  from  fifteen  to 
twenty  years  without  replanting,  returning  a  yield  of  10  to  40  tons 
of  green  feed  per  acre  each  year. 

VALUE   OF   PRICKLY   COMFREY   AS   A    SOILING   CROP   FOR    DAIRY 

COWS. 

It  is  as  a  soiling  crop  for  dairy  cows  that  comfrey  has  proved  of 
most  value.  Dr.  Henry  Foster,  of  Clifton  Springs,  X.  Y.,  has  been 
in  the  past  the  most  enthusiastic  advocate  of  comfrey  for  this  pur- 
pose." Doctor  Foster  top-dressed  his  fields  with  manure  after  each 
cutting  and  cultivated  thoroughly.  In  this  way  he  claimed  to  have 
secured  a,  yield  of  50  tons  per  acre  in  five  cuttings.  According  to 
his  statement  the  cows  ate  it  greedily,  and  no  other  crop  equaled  it 
in  producing  quantity  and  quality  of  milk. 

At  the  New  York  Agricultural  Experiment  Station'7  dairy  cows  at 
first  refused  to  eat  green  comfrey.  Coin  meal  was  then  sprinkled 
over  the  comfrey  ill  the  manger,  hut  it  was  knocked  oil'  and  licked 
up  from  the  bottom  of  the  feed  boxes.  As  a  last  resource,  salt  was 
scattered  oxer  the  comfrey  and  the  animals  were  thus  induced  to  eat 
it.  They  soon  became  fond  of  it  and  afterwards  ate  it  readily  with- 
out salting. 

VALUE  OF  PRICKLY  COMFREY  FOR  FEEDING  HOGS. 

Experiments  were  carried  on  at  the  New  ">  oik  Agricultural  Experi- 
ment Station''  in  which  two  lots  of  hogs,  averaging  64  pounds  each, 
were  led  during  three  weeks  all  the  comfrey  they  would  cat.  in  addi- 


a  Report,  New  York  Agricultural  Experiment  Station,  L887,  \>   72. 

6  Bulletin  22,  n.  s.,  W«  fricultural  Experiment  Station,  pp.292  295. 

I  '  Lr.  17  1 


i ■  i ; i ■  i  \i  i'i;i:\    as    \    fokaue  chop.  , 

t  ic hi  to  "a  little  com  meal.''  The  average  loss  in  weight  of  one  lot 
was  0.9  pound  per  week,  and  of  the  other  lot  1.6  pound-.  This  loss 
was  not  due  to  lack  of  capacity,  since  in  a  similar  experiment  with 
mangolds,  which  contained  as  great  a  percentage  of  water  as  the  eom- 
frey,  the  hogs  ate  twice  a>  much. 

Another  test  with  older  pigs  was  made,  using  for  the  first  six  weeks 
a  ration  com  pose,  I  entirely  of  grain  :  the  next  four  weeks  a  rat  ion  t  hat 
was  ."ai  per  cent  coin  ensilage;  and  the  remaining  five  weeks  of  the 
period  a  ration  containing  50  per  cent  of  comfrey.  The  comfrey  was 
\'n\  I'reshK  cut  and  contained  an  average  of  86.7  per  cent  of  water. 
In  considering  the  cost  per  pound  of  gain,  the  green  comfrey  was 
rated  at  81  a  ton.  In  one  pen  the  comfrey  and  ensilage  were  salted, 
while  in  another  pen  the  green  feed  was  not  salted.  Neither  lot  of 
j)ii^s  made  a  profitable  growth  while  comfrey  was  fed,  and  the  cost 
per  pound  of  gain  in  live  weight  for  the  period  they  were  U'A  comfrey 
was  9.53  cents  in  the  pen  where  sail  was  not  applied  and  6.12  cents 
in  the  pen  where  salt  was  applied,  as  against  3.38  cents  in  the  first 
pen  and  3.07  cents  in  the  second  pen  when  ivd  the  grain  ration. 

VALUE  OF  PRICKLY  COMFREY  AS  HAY  OR  ENSILAGE. 

Regarding  the  use  of  prickly  comfrey,  the  New  York  Agricultural 
Experiment  Station  reports"  as  follows:  "Our  trials  indicate  that  it 
is  of  no  value  either  for  hay  or  ensilage.  Its  use,  therefore,  is  con- 
fined to  that  of  a  soiling  crop."  In  Europe  it  has  been  used  to  sonic 
extent  for  silage,  hut  the  watery  and  gummy  nature  of  the  leaves  is 
apt  to  cause  it  to  heat  in  the  silo  and  acquire  a  disagreeable  odor. 

CROP  YIELDS. 

from  i  |  to  16  tons  of  green  matter  per  acre  are  reported  by  the 
New  York  Agricultural  Experiment  Station."  It>  tons  by  the  Ver- 
mont station.''  f>!  to  17  '  tons  by  the  North  Carolina  station/  and  .".."» \ 
tons  by  t  he  Wisconsin  stat  ion.  ' 

In  dry  matter  the  Wisconsin  Agricultural  Experiment  Station 
reports''  u  yield  of  6,475  pounds  of  comfrey  to  the  acre,  compared  to 
7,'.»s7  pounds  of  red  clover. 

The  Pennsylvania  Agricultural  Experiment  Station  reports'  the 
yield  per  acre  of  digestible  material  in  comfrey.  Kafir  corn,  and 
cowpeas  to  he  as  follows: 

N'ew   York  Agricultural  Experiment  Station,  1888,  pp   332  and  :;.'..'■     IS89, 
[>p.  221  and  222. 

Report,  Vermont  Agricultural  Experiment  Station,  1889,  p 

lletin  168,  North  Carolina  Agricultural  Experiment  Station,  pp.  129   132. 
Re]   irt,  Wisconsin  Agricultural  Experiment  Station,  1889,  pp.  207  ami '.'I  I. 
'  Bulletin  6,  Pennsylvania  Agricultural  Experiment  Station,  pp.  lilt; 
•  7| 


PRICKLY   COMFREY.    AS   A   FORAGE   CROP. 


Fat 

Crude  fiber 

X  i  t  rogen-Iree  extra 

Protein 

Total  digestible  matter 
Total  green  matter. . . . 


Prickly 
eomfrey. 


Pounds. 
30.5 
35.3 
623.  l 
221.0 


909.9 
1G,  500.0 


Kafir  corn.     Cowpeas. 


Pounds. 

34.2 

33.2 

'    907.8 

119.4 


1.094.  0 
1 1 .  000.  0 


Pounds. 
53. 9 

247. 0 
090. 0 
280.9 


1,271.8 

14.500.0 


These  figures  indicate  that  although  the  yield  of  green  matter  is 
greater  in  prickly  eomfrey,  the  real  food  value  is  likely  to  be  less  than 
that  of  the  commonly  grown  forage  crops. 

COMPARISON  OF  PRICKLY  COMFREY  AND  RED  CLOVER. 

At  the  Wisconsin  Agricultural  Experiment  Station  "  equal  areas  of 
red  clover  and  eomfrey  were  planted  in  1887.  The  eomfrey  was  top- 
dressed  heavily  with  stable  manure.  Yields  of  both  were  determined 
the  second  year,  the  cuttings  being  made  with  a  scythe.  The  red 
clover  returned  26  tons  of  green  feed  to  the  acre  in  three  cuttings, 
and  the  eomfrey  33J  tons.  Samples  were  taken  of  the  cuttings  of 
both  crops  and  the  dry  matter  determined.  The  red  clover  pro- 
duced 23  per  cent  more  of  total  dry  matter  and  25  per  cent  more 
protein  in  three  cuttings  than  the  eomfrey  did  in  four.  A  more 
important  difference  between  the  two  crops  is  in  the  lesser  cost  of 
planting  and  harvesting  the  red  clover  and  its  greater  palatability  to 
stock.  It  would  seem  that  prickly  eomfrey  can  not  compete  with 
red  clover  as  a  forage  crop  for  the  general  farmer. 

COMPARISON  OF  PRICKLY  COMFREY  AND  ENSILAGE  CORN. 

In  Michigan  b  eomfrey  was  grown  side  by  side  with  ensilage  coin, 
and  the  trials  "taught  emphatically  that  in  the  soil  and  climate 
existing  at  the  Michigan  station  corn  is  far  superior  as  a  forage  crop 
i  o  eomfrey." 

COMPARISON  OF  PRICKLY  COMFREY  AND  ALFALFA. 

The  older  planting  of  eomfrey  at  the  New  York  Agricultural 
Experiment  Station  during  1889  gave  a  yield  of  14  tons  of  green 
matter  per  acre.  Alfalfa  during  the  same  period  yielded  more  than 
1()  tons  of  green  matter  per  acre. 

DISEASES  OF  PRICKLY  COMFREY  AND  INSECT  ENEMIES. 

Comfrey  has  been  grown  at  the  North  Carolina  Agricultural  Experi- 
ment Stal  ion  since  L899.c  It  grew  well  hut  was  injured  by  both  cater- 
pillars and  a  fungous  disease,  which  reduced  the  crop  to  two  Or  three 

a  Report,  Wisconsin  Agricultural  Experiment  Station,  L889,  pp.  207  and  211. 
&  Bulletin  47,  Michigan  Agricultural  Experiment  Station,  pp.  43  and  44. 
o Bulletin  7:!.  North  Carolina  Agricultural  Experiment  Station,  p.  •">!>. 
[Cir.  47] 


I'Kli   K I . >     t'OMFHKJ      VS     \    b'OKACil     CHOP.  '.I 

cuttings  each  your,  while  many  kills  were  killed  out  entirely  l>y  the 
disease.  When  planted  on  a  thin  soil  with  a  Hard  clay  subsoil, 
the  third  growth  withered  up  during  the  period  of  drought  and  the 
plants  remained  dormant   until  the  following  spring. 

EFFECT  OF  PRICKLY  COMFREY  ON  THE   SOIL. 

The  soil  in  an  <>ld  eomfrey  field  is  usually  left   in  mdition, 

owing  i"  frequent  cultivations  and  to  the  top-dressings  of  barnyard 
manure.  The  large,  fleshy  roots  of  the  eomfrey  also  penetrate  to  a 
considerable  depth  and  add  humus  to  the  subsoil,  where  it  is  usually 
wanting.  Analyses  of  the  materials  removed  from  the  soil,0  however, 
show  that  were  n  not  for  the  constant  application  of  fertilizing 
material  the  growing  of  eomfrey  would  be  decidedly  injurious  to  the 
soil.  Assuming  20  tons  of  green  material  to  the  acre  as  an  average 
crop  of  eomfrey,  there  would  be  removed  from  the  soil  165  pounds 
of  nitrogen,  65  pounds  of  phosphoric  acid,  and  74  pounds  of  potash. 

From  the  present  knowledge  of  prickly  eomfrey,  it  is  advisable 
to  experiment  with  it  only  on  a  small  scale  as  a  soiling  crop.  There 
seems  little  to  justify  its  extended  use  in  a  region  where  alfalfa  or 
red  clover  will  succeed.  Large  yields  have  nol  been  obtained  without 
heavy  applications  of  fertilizer,  and  a  comparison  of  prickh  eomfrey 
with  the  forage  crops  already  in  use  has  usually  resulted  unfavorably 
to  the  eomfrey. 

Approved : 

James  Wilson, 

S\  cretary  of  Agricultun  . 

W  vshington,   I).  ('..   Dea  mbi  r  10,   1909. 


port,  Canada  Experimental   Fair  p.  201 

=  7| 


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